A typical home audio system has one or more input sources coupled to an amplifier or receiver, which in turn is coupled to a set of speakers. In operation, an audio signal generating source, such as a CD (Compact Disc) player is connected to an amplifier input through an input cable. The CD player reads information from the disk, generates an audio signal from the information, and sends a low-level or line-level audio signal to the amplifier over the input cable. The amplifier, in turn, amplifies the signal and drives various speaker outputs that are in turn connected to speakers by speaker wires.
Although twenty years ago home audio systems typically included only two speakers, present “surround” systems now include five or seven speakers for the main audio plus a subwoofer to produce low frequency effects. Commercial applications, such as retail stores or shopping malls may include dozens or hundreds of speakers. Connecting such large number of speakers generally requires a commensurate number of speaker wires originating from the amplifier. Although commercial facilities may be designed with structures equipped to distribute speaker wires, along with other electrical distribution, homes are generally not so equipped. Instead, a typical home includes wires for electrical distribution hidden within walls that are covered by solid wall coverings during construction. It is very difficult to add additional wires within walls once a home is constructed, and thus exposed speaker wire is often an unsightly, though necessary, requirement for most home audio installations.
There have been developments with “powered” audio speakers, which typically include integral amplification and active crossover networks, but these systems lie at the periphery of mainstream home audio. One type of powered speaker that is pervasive in home audio is a powered sub-woofer. Other powered systems include desktop computer speakers, docking systems for personal audio devices, professional audio speakers, and “pro-sumer” monitor speakers.
There have also been some developments with powered “wireless” audio speakers, but these systems are generally proprietary “closed loop” systems, including a particular transmitter being required to operate with a particular receiver. Requiring such matched systems frustrates many consumers of audio products because it generally binds them to purchasing pre-packaged systems, which lack flexibility and may not meet requirements of many consumers. In addition, current wireless speaker systems tend to be small, inexpensive, and characterized by low fidelity.
Embodiments of the invention address these and other limitations of the prior art.